@book{145521,
	author = {Stover, Carl W. and Coffman, Jerry L.,},
	title = {Seismicity of the United States, 1568-1989 (revised)},
	publisher = {U.S. G.P.O.},
	year = {1993.},
	series = {U.S. Geological Survey professional paper},
	address = {Washington}
}